Dumbbell Skull Crusher
(BEST DUMBBELL SKULL CRUSHER WORKOUTS FOR BUILDING MUSCLE AT HOME)
Dumbbell Skull Crusher: A Comprehensive Guide
To do a dumbbell skull crusher, lie on your back holding two dumbbells up with straight arms, bend only your elbows to lower the weights beside your head or toward your forehead, then straighten your arms to lift them back up. It’s a single-joint (isolation) exercise for the triceps, the muscle at the back of your upper arm, and you can do it on the floor or on a flat bench.
This guide will provide you with a detailed overview of how to perform the Dumbbell Skull Crusher, its benefits, and tips for maximizing its effectiveness.
Dumbbell Skull Crusher
1. Exercise Overview
2. Tips for Maximizing Effectiveness
3. Exercise Videos and Related Guides
Before we dive into the specifics, let’s first understand what makes the Dumbbell Skull Crusher an effective exercise for tricep development. This will help you make an informed decision when incorporating it into your routine.
1. Exercise Overview
The dumbbell skull crusher works all three heads of the triceps. Because your upper arms point up at the ceiling, the long head, the only head that crosses your shoulder, works from a more stretched position than in exercises done with your arms by your sides.
Use a weight you can lower slowly and under control, and move only at your elbows, so your triceps do the work rather than momentum.
In the version shown below, you hold the dumbbells with a neutral grip, palms facing each other, and lower them beside your head. Like every skull crusher, it works all three heads of the triceps.
Skull Crushers
How to Perform Skull Crushers
- Prepare Your Position: Lie on your back on the floor with your knees bent, holding the dumbbells above your face with straight arms and a neutral grip, palms facing each other.
- Lower the Weights: Bend your elbows to lower the weights towards each side of your head.
- Press Upwards: Extend your arms to return to the starting position.
- Repeat: Do 8 to 12 slow, controlled reps. Muscle can grow across a wide range of rep counts (Schoenfeld 2021), so pick a weight you can control for the whole set.
The Dumbbell Skull Crusher is an excellent isolation exercise for the triceps.
Dumbbell Skull Crusher
How to Perform Dumbbell Skull Crusher
- Prepare Your Position: Lie on your back on the floor with your knees bent, or on a flat bench, and hold two dumbbells end to end with straight arms, the weights above your face.
- Execute the Movement: Slowly lower the dumbbells towards your forehead by bending your elbows, keeping your upper arms stationary.
- Controlled Return: Once the dumbbells are near your forehead, pause briefly, then extend your arms back to the starting position.
- Repeat: Perform the movement for 8-12 repetitions.
2. Tips for Maximizing Effectiveness
To get the most out of the Dumbbell Skull Crusher, follow these tips to ensure proper form and maximize muscle engagement.
- Maintain Proper Form: Keep your upper arms stationary and avoid using momentum to lift the weights.
- Control the Movement: Perform the exercise slowly and with control, focusing on the stretch and contraction of the triceps.
- Start with Lighter Weights: Begin with lighter weights to master the form before progressing to heavier weights.
- Incorporate into a Balanced Routine: Include the Dumbbell Skull Crusher as part of a well-rounded tricep workout that targets all three heads of the muscle.
Why add an overhead exercise? The long head is the only part of the triceps that crosses your shoulder, so it stretches more when your arms are overhead. A 12-week study had 21 adults train one arm overhead and the other arm by the side, using the same cable triceps exercise:
| Part of the triceps | Arm overhead | Arm by your side |
|---|---|---|
| Long head | +28.5% | +19.6% |
| Lateral and medial heads | +14.6% | +10.5% |
| Whole triceps | +19.9% | +13.9% |
Increase in muscle volume measured by MRI. Source: Maeo 2023. The overhead arm grew more even though it lifted less weight. Skull crushers weren’t tested: in a skull crusher your upper arms point at the ceiling, between these two positions, so pairing them with an overhead move such as the tricep press trains the long head at its longest.
Tricep Press
Remember, achieving optimal tricep development involves maintaining a consistent workout routine and incorporating a variety of exercises. It’s crucial to find activities you enjoy and can perform regularly to maximize the benefits.
Try out the Dumbbell Skull Crusher, and you’ll be on your way to stronger, more defined triceps.
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3. Exercise Videos and Related Guides
Every exercise in this guide has its own page in our free exercise library, with a video demonstration, step-by-step form tips, common mistakes to avoid and the muscles it works:
Browse more in our tricep exercises lists.
Related guides: tricep workouts, lateral head tricep exercises, medial head tricep exercises and how to get bigger arms.
Want a ready-made plan? Dumbbell Home Workout builds dumbbell workouts for every muscle group around your goal, level and schedule.
DUMBBELL SKULL CRUSHER FAQ
Yes. Skull crushers train all three heads of the triceps with just two dumbbells, and you can make them harder over time by adding reps or weight. To work the long head even more, add an overhead exercise such as the tricep press: in a 12-week study, a triceps exercise done with the arm overhead grew the long head about 1.5 times as much as the same exercise done with the arm by the side (Maeo 2023).
Beginners can start with 2 or 3 sets of 8 to 12 slow reps, using a weight you can lower under control. The American College of Sports Medicine suggests 8 to 12 reps for people new to strength training and multiple sets for building muscle. Muscle can also grow with lighter or heavier weights (Schoenfeld 2021), and a review of 15 studies found that more weekly sets built more muscle (Schoenfeld 2017), so add a set as you get stronger and recover well.
Yes. Both skull crusher demos in this guide are done lying on the floor with your knees bent. Lower the dumbbells beside your head or toward your forehead rather than behind it, so they don’t touch the floor, and keep your upper arms still.
The dumbbell skull crusher works the triceps, the muscle at the back of your upper arm, including all three of its heads: the long head, which also crosses your shoulder, and the lateral and medial heads. Your shoulder muscles work to hold your upper arms still.
Twice a week is a good target for most people. A review of training studies found that training a muscle twice a week built more muscle than training it once a week (Schoenfeld 2016). Do them as part of an arm, push or upper-body workout.
REFERENCES
J Strength Cond Res. 2019 May;33(5):1286-1294. Partial Range of Motion Exercise Is Effective for Facilitating Muscle Hypertrophy and Function Through Sustained Intramuscular Hypoxia in Young Trained Men
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